This invention relates to alternate vision systems and more particularly to vehicle mounted proximity sensing systems.
As is known in the art, alternate vision systems are near proximity detection systems designed to be used in conjunction with the mirroring system of a motor vehicle. Such systems alert the driver of the vehicle on which the system is mounted to the existence of an object in a vehicle's blind spot, e.g., that area to the side and rear of the vehicle which is not visible through the use of mirrors or other means. These blind spots generally exist, for example, near the rear ends of a car, next to the rear wheels of a truck or next to the right side of a truck and in particular next to the right side of the cab of the truck.
Often an entire car, motorcycle or other object travelling along side a truck may be totally undetectable by a driver of the truck even after the driver checks his rear view mirrors. Thus, driving blindspots are a significant problem and lead to accidents. This problem will become more frequent as roads become more congested and cars themselves become smaller making them less apt to be viewed through the mirroring system of a larger vehicle such as a truck, for example.
Furthermore, in addition to the blind spots mentioned above, it may be desirable in specialized vehicles to detect an object in the front area of the vehicle. For example a school bus may have a need to detect the presence of small children near a front region of the bus when the children enter and exit the bus.
One solution to this problem is to provide a proximity sensor on every side of a vehicle. Such sensors are typically provided as infrared, radar, or ultrasonic detectors. The sensors are typically coupled to a central computer system which is in turn coupled to a control and display console which is typically disposed where the driver of the vehicle may view the display.
One problem with this approach, however, is that the display console typically does not provide an indication of which sensor is in close proximity to an object. Thus, even though the operator of a vehicle may know that he is in close proximity to some object, he may not be aware of the particular location of the object.
A second problem with this approach is that it is often difficult to determine if the sensors disposed on the vehicles are operating correctly. To determine if the sensors are operating correctly requires a first person bringing an object in proximity to a sensor and a second person viewing the display console inside the vehicle to determine if the sensor is sending a proximity signal to the console.
A third problem with this approach is that such systems generally fail to detect and report the failure of a particular sensor. Thus, it would be desirable to provide a system which detects and indicates the failure of a particular sensor in a plurality of sensors. Furthermore, it would be desirable to have the sensors disposed in a variety of locations on the vehicle.
Moreover, such sensing systems are affected by the weather. Thus it would be desirable to detect the existence of ice and snow, for example, on the sensor and compensate for effects which such weather conditions may have on the sensor.